US4038820A - Two-cycle engine wave interference muffler means - Google Patents

Two-cycle engine wave interference muffler means Download PDF

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Publication number
US4038820A
US4038820A US05/534,082 US53408274A US4038820A US 4038820 A US4038820 A US 4038820A US 53408274 A US53408274 A US 53408274A US 4038820 A US4038820 A US 4038820A
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US
United States
Prior art keywords
exhaust
outlet port
exhaust gas
engine
exhaust pipe
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US05/534,082
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English (en)
Inventor
Magohei Tsukamoto
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Yamaha Motor Co Ltd
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Yamaha Motor Co Ltd
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Filing date
Publication date
Application filed by Yamaha Motor Co Ltd filed Critical Yamaha Motor Co Ltd
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Publication of US4038820A publication Critical patent/US4038820A/en
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Expired - Lifetime legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B27/00—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues
    • F02B27/04—Use of kinetic or wave energy of charge in induction systems, or of combustion residues in exhaust systems, for improving quantity of charge or for increasing removal of combustion residues in exhaust systems only, e.g. for sucking-off combustion gases
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F01—MACHINES OR ENGINES IN GENERAL; ENGINE PLANTS IN GENERAL; STEAM ENGINES
    • F01N—GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES OR ENGINES IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNAL-COMBUSTION ENGINES
    • F01N1/00—Silencing apparatus characterised by method of silencing
    • F01N1/06—Silencing apparatus characterised by method of silencing by using interference effect
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02B—INTERNAL-COMBUSTION PISTON ENGINES; COMBUSTION ENGINES IN GENERAL
    • F02B75/00—Other engines
    • F02B75/02—Engines characterised by their cycles, e.g. six-stroke
    • F02B2075/022—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle
    • F02B2075/025—Engines characterised by their cycles, e.g. six-stroke having less than six strokes per cycle two
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02T—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO TRANSPORTATION
    • Y02T10/00—Road transport of goods or passengers
    • Y02T10/10—Internal combustion engine [ICE] based vehicles
    • Y02T10/12—Improving ICE efficiencies

Definitions

  • the present invention relates to exhaust means for internal combustion engines and more particularly to engine exhaust means which is effective to attenuate noise producing pulsating pressure in engine exhaust gas.
  • exhaust means for internal combustion engines includes an exhaust pipe having an open outlet end from which engine exhaust gas is discharged. Since engine combustion gas is cyclically discharged from an engine outlet port, it produces pulsating pressure in the exhaust pipe. The pulsating pressure thus produced propagates in the exhaust pipe toward the outlet end thereof and is finally discharged from the outlet end.
  • a conventional engine exhaust pipe does not have any means or absorbing or attenuating the pulsating pressure so that it is discharged from the exhaust pipe substantially in the form as it was initially produced.
  • the exhaust gas is introduced from the exhaust pipe into a muffler so that the noise producing pressure in the exhaust gas is substantially attenuated before it is discharged into atmosphere, it has been very difficult to suppress the noise level below an acceptable value unless a bulky muffler is used due to the fact that the pressure pulsation in the exhaust gas includes substantial low frequency components and that the maximum value of the pulsating pressure is high. Particularly, in a motor cycle in which only limited space is available for a muffler, the problem is serious.
  • the present invention has an object to eliminate the aforementioned problem in conventional engine exhaust means.
  • Another object of the present invention is to provide engine exhaust means in which engine exhaust gas is taken out at a position or positions where the maximum amplitude of the noise producing pulsating pressure in the exhaust gas is relatively low.
  • a further object of the present invention is to provide means for modifying engine exhaust gas in which noise producing pulsating pressure can be readily attenuated by a relatively small muffler.
  • exhaust means for internal combustion engines which comprises exhaust pipe means having one end connected with exhaust port means of the engine, the other end of the exhaust pipe means being closed, said exhaust pipe means having a first portion of substantially uniform cross-sectional area which is adjacent to the exhaust port means of the engine, a second portion connected at one end with said first portion and having cross-sectional area increasing toward the other end thereof, and a third portion connected at one end with said second portion and closed at the other end, exhaust gas outlet port means being provided in said exhaust pipe means in said third portion and spaced apart from the closed end of the exhaust pipe means.
  • the engine-exhaust gas is allowed to expand in the exhaust pipe so that the maximum amplitude of the pulsating pressure in the exhaust gas can be decreased. Further, since the exhaust pipe means is closed at the terminal end, the pressure pulsation in the exhaust gas is reflected at the closed end. According to the investigation by the inventor, the maximum value of the pulsating pressure in the exhaust gas is lower in the intermediate portion of the exhaust pipe than in the both end portions thereof.
  • the exhaust gas outlet port is provided at this intermediate portion of the exhaust pipe, particularly in said third portion so that the exhaust gas is discharged from the exhaust pipe with lower pressure level.
  • the arrangement of the present invention is further effective to decrease low frequency components of noise in the exhaust gas. Thus, according to the arrangement of the present invention, it becomes possible to attenuate noise in the exhaust gas by a relatively small muffler.
  • the total length of the exhaust pipe has an important effect on the performance of the engine since the pulsations reflected at the closed end propagates reversely in the exhaust pipe and reach the exhaust port. It has already been proposed to properly determine the length of the exhaust pipe so that a relatively low back pressure is applied at the exhaust port during the scavenging phase of the engine operation to facilitate initial scavenging of the exhaust gas while a relatively high back pressure is applied during compression stroke to prevent excessive amount of combustible mixture from escaping through the exhaust port.
  • the distance between the exhaust gas outlet port means and the closed end of the exhaust pipe has an important effect on the amplitude of the pulsations at the outlet port means from what the gases exit.
  • the total length of the exhaust pipe can be determined as desired simply by increasing or decreasing the length of the first portion having the constant cross-sectional area without any effect on the nature of the pulsations taken out of the outlet port means.
  • FIG. 1 is a vertical sectional view of a two-cycle engine equipped with an exhaust pipe made in accordance with the present invention
  • FIG. 2 is a sectional view taken along the line II--II in FIG. 1;
  • FIG. 3 is a vertical sectional view of a two-cycle engine having an exhaust pipe in accordance with another embodiment of the present invention.
  • FIG. 4 is a diagram showing the change in maximum pressure along the length of the exhaust pipe.
  • a two-cycle engine 1 of conventional construction including a cylinder 2 and a piston 3 which reciprocates in the cylinder 2.
  • the cylinder is provided with scavenging ports (not shown) and an exhaust port 4 which leads to an exhaust passage 5.
  • An exhaust pipe 6 is connected at one end with the exhaust passage 5 and has an upstream or first portion 6a of substantially uniform cross-sectional area.
  • the uniform first portion 6a continues to an expansion cone or second portion 6b which gradually increase in cross-section toward the downstream side.
  • a cylindrical third portion 6c of substantially uniform cross-section which further continues to a contraction cone 6d.
  • the terminal end of the contraction cone 6d is closed by a cup-shaped end portion 6e.
  • an expansion chamber 7 by the expansion cone 6b, the cylindrical portion 6c and the contraction cone 6d.
  • the exhaust pipe 6 is provided at the cylindrical portion 6c with an exhaust gas outlet port 8 which is connected with a downwardly directed outlet conduit 9.
  • combustion gas is cyclically discharged from the exhaust port 4 in the cylinder 2 into the exhaust pipe 6 and noise producing pulsating pressure propagates along the length of the exhaust pipe 6.
  • the exhaust gas is allowed to expand in the chamber 7 so that the maximum amplitude of the pulsating pressure is substantially decreased.
  • FIG. 4 shows the change in the maximum pressure along the length of the exhaust pipe 6.
  • the pulsation in the exhaust gas is reflected at the contraction cone 6d and the closed end 6e and then proceeds in the reverse direction.
  • the exhaust gas outlet port 8 is subjected to pulsating pressure from the engine exhaust port 4 and the pulsating pressure reflected by the portions 6d and 6e, whereby pulsation of higher frequency is taken out of the outlet port 8.
  • the noise producing accoustic waves in the exhaust gas discharged from the exhaust pipe 6 through the outlet 8 can be readily attenuated by conventional muffler means of smaller dimension.
  • a conventional muffler including noise absorbing materials such as glass fibers which are effective to attenuate the high frequency pulsations.
  • FIG. 3 shows another embodiment of the present invention.
  • the cylindrical portion 16c defining an expansion chamber 17 is provided with two axially spaced apart outlet ports 18a and 18b which are connected together by an external conduit 19 which is formed with perforations 20 at the intermediate portion thereof.
  • the position of the perforations may be so determined that pulsations from the ports 18a and 18b reach these with 180° of phase difference.
  • a housing 21 having an outlet opening 22 encompasses the perforated area of the conduit 19.
  • the arrangements of the embodiment are identical to those in the previous embodiment so that the details will not be described further.
  • the length of the conduit 19 is so determined that the pulsations from the port 18a interfere with those from the port 18b at the area of the perforations 20 so that the pulsations can be substantially attenuated before they are discharged from the outlet port 22.
  • the outlet ports 8 and 22 may of course be connected with conventional muffler means for further attenuating the noise producing pulsation.

Landscapes

  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Exhaust Silencers (AREA)
US05/534,082 1973-12-25 1974-12-18 Two-cycle engine wave interference muffler means Expired - Lifetime US4038820A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
JA49-3768 1973-12-25
JP49003768A JPS5095632A (enrdf_load_stackoverflow) 1973-12-25 1973-12-25

Publications (1)

Publication Number Publication Date
US4038820A true US4038820A (en) 1977-08-02

Family

ID=11566335

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/534,082 Expired - Lifetime US4038820A (en) 1973-12-25 1974-12-18 Two-cycle engine wave interference muffler means

Country Status (6)

Country Link
US (1) US4038820A (enrdf_load_stackoverflow)
JP (1) JPS5095632A (enrdf_load_stackoverflow)
CA (1) CA1042808A (enrdf_load_stackoverflow)
DE (1) DE2461085A1 (enrdf_load_stackoverflow)
FR (1) FR2255472B1 (enrdf_load_stackoverflow)
GB (1) GB1487400A (enrdf_load_stackoverflow)

Cited By (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4449608A (en) * 1980-10-20 1984-05-22 Kawasaki Jukogyo Kabushiki Kaisha Exhaust device for 2-cycle engine
US4719988A (en) * 1985-07-08 1988-01-19 Kawasaki Jukogyo Kabushiki Kaisha Muffler
US5388408A (en) * 1993-10-01 1995-02-14 Lawrence-Keech Inc. Exhaust system for internal combustion engines
US6698194B2 (en) * 1999-09-22 2004-03-02 Aktiebolaget Electrolux Two-stroke internal combustion engine
US20050230182A1 (en) * 1999-08-05 2005-10-20 Faurecia Systemes D'echappement Exhaust volume
US20080041657A1 (en) * 2006-06-30 2008-02-21 Toyoda Gosei Co., Ltd. Muffler duct
US20100051379A1 (en) * 2008-09-02 2010-03-04 Charles Graves Enhanced Exhaust System

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS60142009A (ja) * 1983-12-28 1985-07-27 Ishikawajima Shibaura Kikai Kk ２サイクルエンジンの排気装置
RU2283433C1 (ru) * 2005-01-24 2006-09-10 Николай Иванович Максимов Способ глушения шума выхлопа продуктов сгорания из цилиндра двс и двс для его осуществления

Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1601884A (en) * 1925-02-04 1926-10-05 Gregory V Rylsky Muffler for internal-combustion engines
US2075265A (en) * 1935-08-09 1937-03-30 Maxim Silencer Co Sound attenuating device
US2109995A (en) * 1935-08-01 1938-03-01 Hawle Josef Silencer for internal combustion engines
DE1121410B (de) * 1958-03-27 1962-01-04 Wilhelm Bauer Schalldaempfer fuer Brennkraftmaschinen
US3568791A (en) * 1968-02-27 1971-03-09 Univ Sydney Air ducting
US3665712A (en) * 1970-02-09 1972-05-30 William L Tenney Two-cycle engine resonance exhaust system
US3744589A (en) * 1972-06-09 1973-07-10 Gen Motors Corp Swirling flow muffler
US3776364A (en) * 1972-04-28 1973-12-04 Donaldson Co Inc Noise reduction apparatus and method
US3842599A (en) * 1972-12-18 1974-10-22 Mcculloch Corp Exhaust system for a two-cycle engine
US3875744A (en) * 1972-12-18 1975-04-08 Mcculloch Corp Exhaust method and apparatus for a dual cylinder two-cycle engine

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPS4528188Y1 (enrdf_load_stackoverflow) * 1967-10-11 1970-10-30

Patent Citations (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US1601884A (en) * 1925-02-04 1926-10-05 Gregory V Rylsky Muffler for internal-combustion engines
US2109995A (en) * 1935-08-01 1938-03-01 Hawle Josef Silencer for internal combustion engines
US2075265A (en) * 1935-08-09 1937-03-30 Maxim Silencer Co Sound attenuating device
DE1121410B (de) * 1958-03-27 1962-01-04 Wilhelm Bauer Schalldaempfer fuer Brennkraftmaschinen
US3568791A (en) * 1968-02-27 1971-03-09 Univ Sydney Air ducting
US3665712A (en) * 1970-02-09 1972-05-30 William L Tenney Two-cycle engine resonance exhaust system
US3776364A (en) * 1972-04-28 1973-12-04 Donaldson Co Inc Noise reduction apparatus and method
US3744589A (en) * 1972-06-09 1973-07-10 Gen Motors Corp Swirling flow muffler
US3842599A (en) * 1972-12-18 1974-10-22 Mcculloch Corp Exhaust system for a two-cycle engine
US3875744A (en) * 1972-12-18 1975-04-08 Mcculloch Corp Exhaust method and apparatus for a dual cylinder two-cycle engine

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4449608A (en) * 1980-10-20 1984-05-22 Kawasaki Jukogyo Kabushiki Kaisha Exhaust device for 2-cycle engine
US4719988A (en) * 1985-07-08 1988-01-19 Kawasaki Jukogyo Kabushiki Kaisha Muffler
US5388408A (en) * 1993-10-01 1995-02-14 Lawrence-Keech Inc. Exhaust system for internal combustion engines
US20050230182A1 (en) * 1999-08-05 2005-10-20 Faurecia Systemes D'echappement Exhaust volume
US7240769B2 (en) * 1999-08-05 2007-07-10 Faurecia Systemes D'echappement Exhaust volume
US6698194B2 (en) * 1999-09-22 2004-03-02 Aktiebolaget Electrolux Two-stroke internal combustion engine
US20080041657A1 (en) * 2006-06-30 2008-02-21 Toyoda Gosei Co., Ltd. Muffler duct
US7556123B2 (en) * 2006-06-30 2009-07-07 Toyoda Gosei Co., Ltd. Muffler duct
US20100051379A1 (en) * 2008-09-02 2010-03-04 Charles Graves Enhanced Exhaust System

Also Published As

Publication number Publication date
JPS5095632A (enrdf_load_stackoverflow) 1975-07-30
FR2255472A1 (enrdf_load_stackoverflow) 1975-07-18
FR2255472B1 (enrdf_load_stackoverflow) 1980-04-11
GB1487400A (en) 1977-09-28
CA1042808A (en) 1978-11-21
DE2461085A1 (de) 1975-07-03

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